Purdue Finishes First Phase Of National Air Emissions Study

Purdue University has wrapped up its work in collecting data on the two-year National Air Emissions Monitoring Study requested by the Environmental Protection Agency to look at air quality issues on and around livestock and poultry farms

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Purdue University has wrapped up its work in collecting data on the two-year National Air Emissions Monitoring Study requested by the Environmental Protection Agency to look at air quality issues on and around livestock and poultry farms.

Lead researcher Al Heber, a professor of agricultural and biological engineering at Purdue, says the data has been submitted to the EPA and a summary report provided to the agency.

But much more remains to be done. The next phase is studying and publishing the dynamics and causes of the emissions and “mining” the extensive data for more information.

For its part, EPA is using the data to develop formulas that could be used by animal feeding operations or agencies to estimate their emissions.

“What we collected is baseline data,” Heber says. “The quantity of emissions depends on how waste is collected, treated and stored; the number and type of animals; and the weather.”

In all, Heber and his team collected data from more than 2,300 sensors at a total of 38 barns on 14 farms in California, Indiana, Iowa, New York, North Carolina, Oklahoma, Washington and Wisconsin. Data was collected from five pork production sites, five dairy sites, three egg-layer sites and one broiler ranch. Outdoor swine and dairy lagoons were monitored at nine farms and a dairy corral in Texas was also tested.

At the sites, measurements were collected for emissions of ammonia, hydrogen sulfide, three sizes of particulate matter and volatile organic compounds. Emission rates were calculated every minute.

“The dataset is very extensive,” Heber says. “If we were to analyze one million data points every day, it would take us seven years to analyze – and that’s just for the barns.”

Estimates for emissions collected at any given type of farms will most likely be calculated from barn temperatures, animal density in the barns and barn airflow rate. Farm type is a major factor as for example, greater amounts of hydrogen sulfide are emitted from swine barns than from dairy freestall barns. And the type of manure collection systems, such as flushing vs. scraping manure from barns, influences the numbers

The National Pork Board, National Chicken Council, National Milk Producers Federation and American Egg Board provided funding for the research through the Agricultural Air Research Council.

The EPA’s Office of Air Quality Planning and Standards is developing models to estimate emissions based on the data.

Collaborating with Purdue researchers on the project were Cornell University, Iowa State University, North Carolina State University, Texas A&M University, the University of California-Davis, the University of Minnesota and Washington State University.